Fermiite
| Fermiite | |
|---|---|
| General | |
| Category | Sulfate mineral |
| Formula (repeating unit) | Na4(UO2)(SO4)3·3H2O |
| Crystal system | Orthorhombic |
| Crystal class | Pyramidal (mm2) H-M symbol: (mm2) |
| Space group | Pmn21 |
| Unit cell | a = 11.84, b = 7.87 c = 15.33 [Å] (approximated); Z = 4 |
| Identification | |
| Color | Pale greenish-yellow |
| Crystal habit | prismatic |
| Cleavage | None |
| Tenacity | Brittle |
| Mohs scale hardness | 2.5 |
| Streak | White |
| Diaphaneity | Transparent |
| Density | 3.31 (calculated); 3.23 (measured) |
| Optical properties | Biaxal (+) |
| Refractive index | nα=1.52, nβ=1.53, nγ=1.57 (approximated) |
| Pleochroism | Colourless (X & Y), pale greenish-yellow (Z) |
| 2V angle | 50o (calculated) |
| Other characteristics |  Radioactive |
| References | [1][2] |
Fermiite is a rare uranium mineral with the formula Na4(UO2)(SO4)3·3H2O.[3] Chemically related minerals include oppenheimerite, meisserite (which is also structurally-related to fermiite),[2] belakovskiite, natrozippeite and plášilite.[4][5][6][7][8] Fermiite comes from the Blue Lizard mine, San Juan County, Utah, USA, which is known for many rare uranium minerals.[1][2][9] The name honors Enrico Fermi (1901–1954).[2]
Association
Fermiite is closely associated with numerous other sulfate minerals: oppenheimerite, bluelizardite, wetherillite, blödite, manganoblödite, chalcanthite, epsomite, gypsum, hexahydrite, kröhnkite, sideronatrite and tamarugite.[3]
Crystal structure
The main building block of the crystal structure of fermiite is a chain of the composition (UO2)(SO4)3. Chains are connected with five types of Na-O polyhedra.[3]
References
- ^ a b Kampf, A.R., Plášil, J., Kasatkin, A.V., Marty, J., and Čejka, J., 2015. Fermiite, Na4(UO2)(SO4)3·3H2O and oppenheimerite, Na2(UO2)(SO4)2·3H2O, two new uranyl sulfate minerals from the Blue Lizard mine, San Juan County, Utah, USA. Mineralogical Magazine 79(5), 1123-1142
- ^ a b c d "Fermiite: Fermiite mineral information and data". Mindat.org. Retrieved 2016-03-04.
- ^ a b c Kampf, A.R., Plášil, J., Kasatkin, A.V., Marty, J., and Čejka, J., 2015. Fermiite, Na4(UO2)(SO4)3·3H2O and oppenheimerite, Na2(UO2)(SO4)2·3H2O, two new uranyl sulfate minerals from the Blue Lizard mine, San Juan County, Utah, USA. Mineralogical Magazine 79(5), 1123-1142
- ^ "Oppenheimerite: Oppenheimerite mineral information and data". Mindat.org. Retrieved 2016-03-10.
- ^ "Meisserite: Meisserite mineral information and data". Mindat.org. Retrieved 2016-03-10.
- ^ "Belakovskiite: Belakovskiite mineral information and data". Mindat.org. Retrieved 2016-03-10.
- ^ "Natrozippeite: Natrozippeite mineral information and data". Mindat.org. Retrieved 2016-03-10.
- ^ "Plášilite: Plášilite mineral information and data". Mindat.org. Retrieved 2016-03-10.
- ^ "Blue Lizard Mine, Chocolate Drop, Red Canyon, White Canyon District, San Juan Co., Utah, USA - Mindat.org". Mindat.org. Retrieved 2016-03-04.